pcie power

I was working on my computer and I unplugged my graphics card (gtx 1080) to get at some cables. I restarted the computer once I was done, but I forgot to connect the pcie power cable to the card. Now, the computer won't post, and my motherboard gives VGA errors when it tries to start. I...

I currently have a gtx 970 and a seasonic 520W psu(non modular). A few minutes after starting any game my display goes blank and shows message please connect to a output source but the PC fans and the lights on the peripherals are still on. If I switch of the mains and start the PC again I get...

I have a Dell Precision Tower 5810 with a 685W PSU and it has an external power board to power the CPU power, PCI etc. This is the link to the board: https://www.ebay.co.uk/itm/362512033183. I noticed on the board an 8-pin connector that is split up into 2x 6-pins, but the graphics card I want...